Brake



y 3 R. s ANoRn I 1,756,996

BRAKE Filed Aug. 25, 19128 IINVENTOR Patented May 6, 1930 UNITED STATES ROY S. SANFORD, OF SOUTH BEND, INDIANA, ASSIGNOR TO BENDIX BRAKE COMPANY,

PATENT OFFICE OF CHICAGO, ILLINOIS. A CORPORATION OF ILLINOIS BRAKE Application filed August 25, 1926. Serial No. 131,350.

This invention relates to brakes, and is illustrated as embodied in an internal expanding automobile brake. An object of the invention is to lessen the friction loss in the brake-applying means, for example by pro- Figure 1 is a vertical section through the viding. novel rollers which are preferably adjustable to take up for the wear of the brake.

In one desirable arrangement the rollers are mounted on the ends of the brake shoes, 'or equivalent friction means, by novel means providing for shifting them bodily to give the desired adjustment, for example by mounting them on angularly-adjustable levers pivoted on the shoes. Various features of novelty relate to the mounting and adjustment of these levers.

The above and other objects and features of the invention, including various novel combinations of part-s and desirable particular constructions, will be apparent from the following description of one illustrative embodiment shownin the accompanying drawing, in which:

brake just inside the head of the brake drum, showing the shoes'in-jside elevation;

Figure 2 is a partial section through the end of one shoe, 011 the line 2-2 of Figure 1, showing the roller and'lever in plan; and

Figure 3 is a partial section through the adjusting means for one; of the rollers.

The brake illustrated includes a rotatable drum 10,1at the openside of which is a suitable support such as a backing plate 12. The friction device of the brake may include three shoes 14. 16. and 18, shoe 14 being anchored on a pivot 20, shoe 16 being anchored on a pivot 22, and shoe 18 being connected to shoe 16 by a fioatingpivot 26. The brake is ap plied by forcing shoes 14 and 18 apart against the resistance ofa-return spring 28, shoe 16 being applied by shoe 18 against the resistance. of an auxiliary return spring 30. The idle position of shoeI'16 may be determined by any suitable stopv.32-. Except as further described below, the above-listed parts or their equivalents may be of any desired construction, the present invention relating to the means for applying thevbrake.

This brake-applying means is shown as including a novel thrust member such as a double cam 34-rocked by a suitable camshaft, and engaging rollers 36 and 38 rotatably mounted on the ends of shoes 14 and 18. The cam 34 is shown with an end flange 40 engaging the ends of the rollers and confining the shoe ends against lateral movement.

Each of the rollers is rotatably mounted on a spindle 42 carried by the ends of a pair of bellcrank levers 44 and 46 on opposite sides of the shoe end, the levers havingan integral connecting part 48 passing through an opening 50 in the web of the shoe. Thus levers 44 and 46 and the connecting part 48 may be regarded, if desired, as a single novel rollercarrying lever.

The levers are fulcrumed on pivots 52 carried by extensions of the shoe webs, with the roller-carrying arms extending radially of the drum so that the rollers 01 other thrust I members are in the angles between those web extensiohsand the ends of the shoes.

The web extensions of shoe 14 extends further inward radially ,of the drum, so that roller 38 engages the cam 34 between the cam axis and the axis of drum 10, while roller 36 engages the cam between thecam axis and the outside ofthe drum. I prefer to form the cam 34 on its opposite sides with cylindrical surfaces or pockets 35 fitting over the rollers to determine the idle position of the cam, the se cylindrical surfaces 37 merging into cam surfaces which wedge the rollers apart in applying the brake. Since the roller 36 onthe end of shoe 18 has approximately twice as far to .go in applying the brake as has roller 38 on shoe 14, because of having to take up the clearance of the two shoes 18 and 16, the distance radially of the brake drum from the axis of cam 34 to the cylindrical surface embracing roller 36 is approximately double the distance from that y axis to the cylindrical surface embracing roller-'38;

Adjustment of the levers is made by means such as stops or setscrews 54 threaded through the shoe webs insideof the openings 50, and engaging the connectingparts 48. The setscrews may if desired be provided with locknuts 56. If preferred, ball spring locks 58 may be provided for the setscrews.

It will be seen that the setscrews 54 may.

be manipulated to rock-the levers to shift rollers 36 and 38 toward and from the axis of cam 3,4, along arcs which are substantially perpendicular to the drum radii.

While one illustrative embodiment has been described in detail, it is notmy intention to limit the scope of the invention to that particular embodiment, 'or'otherwise than by the, terms of the appended claims,

1. A brake comprising, in combination, a drum, a frictiondevice engageable with the drum, a brake-applying device adjacent the ends of the friction device, rollers carried by -.one of said devices and engaging -the other, T and a device carried entirely by each of said, ends for bodilyshifting the correspondingroller to adjust for wear of-the' friction device. j

2. A brake comprising, in combination, a

drum, a brake-applying device adjacent the ends of the friction device-rollers carriedby' the ends of the friction device andengaging the brake applying device, and a device carried entirely by each of said ends for bodily. shifting the corresponding roller to adjust for wear of the friction-device.

3. A brakeshoe havingfin combination, a.

lever pivoted at one end of the shoe, a thrust member on the lever, and means on the shoe I for adjustingi-t-he-lever angularly to shift said member lengthwise of the shoe to take, upforwean 4. A-brake shoe pivoted on the shoe between its ends, and

means on the shoe engaging the other end ofithe lever to adjust it to shift thethrust member.

5. A brakeshoe-having,

a stopcari'ied'by'the shoe and engaged by the other end'of the lever when thrust is applied;

'- to said member. 9

' 6.- A brake shoehaving a web formed with an opening, in combination with a thrust lever pivoted on the shoe-and having a part insaid opening, and a stop on the side of'said opening and engaged by the lever when thrust is applied thereto.

8, A brake shoe havin a web with an openin in combination wlth a pair of levers pivotal y mounted on opposite sides of the in combination, a lever carrying at one end a thrust member and pivoted on the shoe between its ends, and

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shoe and having at one enda connecting part passing through said opening. v

9. A brake shoe having a web with an opening, in combination with a pair of'levers pivotally mounted on opposite-sides of the shoe and having atone end a connecting part passing through said opening, together with a thrust roller rotatably mounted between the unconnected ends of the levers.

' 10. A brake shoe having a'web with an opening, in combination with a pair of levers pivotally mounted on opposite sides of, the

' shoe and having at one end a connecting part passing through said opening, together with a limiting stop engaging said connectingpart. I '11. A brake shoe having a web with an opening, in combination with a pair of levers pivotally mounted on opposite sides of the shoe and having at one end a connecting part passing through said opening, together with a setscrew threaded through part of the Web and engaging the connectingpart;

12. A brake" shoe having an extension at its inner edge at one end, in combination with a bellcrank lever pivoted on .said extension and-having one,end extending substantially radially outward, and a thmlst member carried by the lever .in the angle between said extension and the end of the shoe, the-other end of the bell crank lever extending along the side of the shoe and engaging a part carried by the shoe.

13, A' brake comprising, in combination,

a drum, a friction device having parts of difl'erent lengthsand having a roller 1'0- a p tatably mounted at each end, and a cam havhaving, in combination, alever carrying at one end a thrust member and ing on its opposite sides cylindrical surfaces fitting against the rollers and determining the relative idle positions of the cam and the rollers and merging into cam surfaces wedgr'ingagainst the rollers'when the cam is turned In testimony whereof, I have hereuntosigned my'name.

ROY s; SANFORD.

having a web formed with 

